Most server systems are of identical design as regards climatic construction. The hard drives and operable drives are provided at the front face, followed by a bank of fans with the system fans and, behind that the system board and possibly also the power supply.
Individual components are fitted locally with heat sinks. The CPU has a heatpipe cooler and the chipset on the system board generally has an aluminium cooler. Additional circuits or heat-generating components have possible additional cooling attachments.
Cooling is normally effected by moving air generated by the system fans. The minimum required speed of the fans is determined by those components unfavorably located with respect to the air flow or are thermally critical. These include in particular capacitors, DC/DC converter modules, PCI expansion cards and back-up batteries.
Because of these thermally critical components or elements, the system fans have to be operated at a certain speed. The higher the fan speed has to be, the greater is the noise emission of the fan and power consumption required by the fans.
It is desirable, however, for the servers to be quieter and consume less power.
It could therefore be helpful to reduce the minimum fan speed required or in the best case to enable the fan to be switched off completely.